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Finding the Fourth Proportional to 660.88, 911.82 and 398.71

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Solution

The fourth proportional to 660.88, 911.82 and 398.71 is: 550.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.88 : 911.82 = 398.71 : x
  2. Step 2: Convert to fraction form
    660.88/911.82 = 398.71/x
  3. Step 3: Cross multiply
    660.88x = 911.82 × 398.71
  4. Step 4: Simplify right side
    660.88x = 363,551.75
  5. Step 5: Solve for x
    x = 363,551.75/660.88
  6. Step 6: Final answer
    x = 550.10

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.